What is Intermittent Fasting?

Today, it seems that people are willing to try any health trend that comes along, no matter how odd it sounds. From eating only plants to eating only meat, from juice cleanses to detoxes…it can seem like every diet promises to promote health, lose weight, and improve fitness. 

Many dietary strategies, however, don’t focus on what you should eat, but rather how you should eat it. 

Intermittent fasting (IF) is one approach to health that focuses more on the how. More accurately, IF is all about the timing of your meals, rather than strictly dictating what you can and cannot eat.

 

So, What Exactly is Intermittent Fasting?

Simply put, IF is an approach to eating that revolves around “regular fasting.” 

The idea consists of times when you do not eat (i.e., fasting) and has been around since Bible times. There have been several different schedules described for intermittent fasting, but the most popular involves fasting for 16 hours out of every 24-hour day. It’s important to note that even while fasting, you are permitted to drink water and other no-calorie beverages such as coffee and tea.

 

What’s the Science Behind Intermittent Fasting?

Scientists have thoroughly investigated the effects of IF in animals such as mice. Based on a wide body of research, scientists have found that IF causes widespread changes, like the way that DNA is read and used to make proteins throughout our bodies. These changes occur in the presence of other changes, including an increase in human growth hormone, as well as improved insulin sensitivity and the initiation of our body’s repair systems on the cellular level. 

Based on this available research, scientists have concluded that our bodies seem to respond in a favorably to fasting. This suggests that IF may be an appropriate strategy to help address obesity, diabetes, and other chronic medical conditions.

 

What Are Some of the Potential Benefits of Intermittent Fasting?

People who regularly practice IF report that they feel improved energy and a sense of well-being as some of the main effects of IF. Some of the following are reported benefits of IF which have been backed-up with research…

Increased Human Growth Hormone (HGH)

HGH is an important hormone that helps regulate insulin in the body. Dysregulated insulin and insulin resistance have been shown to be part of the disease of diabetes. Also, higher levels of HGH improve muscle growth (1).

Improved HDL

HDL is high-density lipoprotein, the “good” form of cholesterol in the body. Research in humans showed that IF improved HDL, and improved HDL has been shown to lead to overall lower risk for heart attacks (2)

Weight loss

Several studies have shown that an IF is associated with a reduction in overall weight and, more importantly, waist size, which is an important measure of obesity (3).

Increased Life Span

Although the results have not been convincingly repeated in human studies, previous research in animals found that an IF diet was associated with increased longevity (4).

 

Conclusion

Intermittent fasting is an approach to eating that involves alternating periods of eating nothing and drinking only calorie-free liquids with periods of eating as desired. Research has shown that periods of fasting cause real, measurable changes in specific cells within our body. 

These changes may be associated with certain benefits such as weight loss, lower risk for cardiovascular disease, and even potentially living a longer life!

 

References

1. Hartman ML, Veldhuis JD, Johnson ML, et al. Augmented growth hormone (GH) secretory burst frequency and amplitude mediate enhanced GH secretion during a two-day fast in normal men. J Clin Endocrinol Metab. 1992;74(4):757-765.
2. Heilbronn LK, Smith SR, Martin CK, Anton SD, Ravussin E. Alternate-day fasting in nonobese subjects: Effects on body weight, body composition, and energy metabolism. Am J Clin Nutr. 2005;81(1):69-73.
3. Barnosky AR, Hoddy KK, Unterman TG, Varady KA. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: A review of human findings. Transl Res. 2014;164(4):302-311.
4. Sogawa H, Kubo C. Influence of short-term repeated fasting on the longevity of female (NZB x NZW)F1 mice. Mech Ageing Dev. 2000;115(1-2):61-71.